Unopposed IL-36 Activity Promotes Clonal CD4(+) T-Cell Responses with IL-17A Production in Generalized Pustular Psoriasis

Arakawa, Akiko; Vollmer, Sigrid; Besgen, Petra; Galinski, Adrian; Summer, Burkhard; Kawakami, Yoshio; Wollenberg, Andreas; Dornmair, Klaus; Spannagl, Michael; Ruzicka, Thomas; Thomas, Peter and Prinz, Jörg C. (2018): Unopposed IL-36 Activity Promotes Clonal CD4(+) T-Cell Responses with IL-17A Production in Generalized Pustular Psoriasis. In: Journal of Investigative Dermatology, Vol. 138, No. 6: pp. 1338-1347

Abstract

Generalized pustular psoriasis (GPP) is the most severe psoriasis variant. Mutations in the IL-36 antagonist IL36RN, in CARD14 or AP1S3 provide genetic evidence for autoinflammatory etiology but cannot explain its pathogenesis completely. Here we demonstrate that unopposed IL-36 signaling promotes antigen-driven and likely pathogenic T-helper type 17 (Th17) responses in GPP. We observed that CD4(+) T cells in blood and skin lesions of GPP patients were characterized by intense hyperproliferation, production of the GPP key mediator, IL-17A, and highly restricted TCR repertoires with identical T-cell clones in blood and skin lesions, indicating antigen-driven T-cell expansions. The clonally expanded CD4(+) T cells were major producers of IL-17A. IL-36 signaling substantially enhanced TCR-mediated proliferation of CD4(+) T cells. Moreover, GPP patients showed preferences for HLA-DRB1*14, HLA-DQB1*05, and HLA-DQB1*03. We conclude that in GPP unopposed IL-36 signaling and certain HLA-class II alleles may cooperate in promoting antigen-driven Th17 responses, which in the obvious absence of exogenous triggers may reflect autoimmune reactions. This study reveals a pathogenic pathway where innate immune dysregulation promotes T-cell-mediated inflammation in GPP.

• Item Type: Journal article
• Faculties: Medicine
• Subjects: 600 Technology > 610 Medicine and health
• ISSN: 0022-202X
• Language: English